Boring-bar.



I F. DIEBOLD.

BORING BAR.

APPLICATION FILED JUNE 5.191 5. 1,177,173. Patented Mar. 28,1916.

. Fi 2 is a side elevation of the borin bar pnrrnn am s mama UFFJIJE.

. .IRANK DIEBOLID, 0F MUSKEGON, MICHIGAN.

"BoRINGmA-ia.

To aZZwkom it may concern: 7 7

Be it known that I, FRANK DIEBOLD, a citizen of the United States ofAmerica, residing at Muskegon, in the county of Muskegon and State ofMichigan, have invented certain new and useful Improvements inBoring-Bars; and I do hereby declare the following tobe a full. clear,and exact description of the invention, such as. will enable othersskilled in the art to which it appertains to make and use the same.

This invention relates to a boring bar of the type in which a floatingcutter is to be used.

It is the obiect and purpose of the invention to provide a boring barwith adjusting means to bear against and aline the cutter, yet at thesame time permit its free movement with respect to the bar, and inconjunction with said means provide a new and lmproved lockingconstruction which will hold it rigidly in any position to which it maybe adjusted.

Other objects and purposes consisting of novel and useful features ofconstruction will appear as understanding is had of the embodiment ofthe invention shown in the accompanying drawings. in which:

Figure 1 is a vertical section taken through the forward end of theboring bar.

parts being broken away and shown in section to disclose the cuttermounted therein;

and Fig. 3 is a view similar to Fig. 1 but in a plane at right anglesthereto with the cutter removed from the bar.

Like reference characters refer to like parts throughout the severalviews of the drawing.

The boring bar shown at 1 has a trans verse slot 2 cut therein near itsforward end adapted to receive the cutter 3 which at its rear edge bearsagainst a cylindrical member 4 pivotally mounted between its ends on thepin 5. It will be noted in this connection that the recess receiving thecylinder 4 is of slightly larger diameter than the cylinder leaving aspace as indicated at 6 back of the cylinder whereby it may have alimited pivotal movement about the pin 5. This pivotal movement however.at most will be limited to a few thousandths of an inch.

The forward end of the bar is reduced in size as shown at 7 and is screwthreacled to Specification of Letters Patent.

Patented'Mar. 28, 1916.

Application filerljJu'ne 5, 19.15. .$eria1l\T.o.32,443.

receive-anadjusting collar 8. The rear side of the collar 8 is machinedto an accurate plane and when turned on the extension 7 bears againstthe forward edgeof the cutter 3. In practice the collar is turned sothat it barely engages the cutter permittingcit to move back and forthin the slot 2. If

, any dirtor other foreignmaterial gets between the rear edge of thecutter and the cylinder 4 it is compensated for in the pi votal movementof the cylinder about the pin 5 so that under all conditions, the cutterlies in a true plane exactly at right angles to the axis of the boringbar. being governed by the plane of the rear side of collar 8.

The collar when adiusted in position so as to leave the cutter free oras it is termed floating, must be locked against movement thereafter. Toaccomplish this a cylindrical opening is made transversely of thereduced extension 7 to the bar in which are placed two opposed plugs 9,at their inner ends cut at an incline as indicated at 10 and at theirouter ends threaded so as to engage with the threads of the collar 8.The inclined sides 10 receive therebetween the conical end 11 of ascrew-threaded stud 12 adapted to be manually operated by the head 13.On operating this stud inwardly the conical end thereof forces the plugs9 against the inner sides of the collar 8 and in this manner locks itrigdly against mo ment. At any time the collar may be unlocked and freedfor movement by merely releasing the plugs 9 by proper operation of thestud.

From the foregoing it will be clear that I have provided a very simplyconstructed boring bar and one in which floating cutters may be used toadvantage. The construction comprises few parts and in practice hasdemonstrated its utility and serviceability. At any time the rear sideof the collar may be planed and corrected if it gets out of truealinement and at all times the bar is practically proof against gettingout of order.

I claim:--

1. In combination. a boring bar having a transverse openingtherethrough, a cylinder pivotally mounted between its ends at the rearof said opening, said cylinder having a limited pivotal movement, athreaded front extension to the boring bar, a collar adjustable hack andforth on the extension,

a pair of plugs movably mounted in a transverse opening in theextension, each plug having an outer threaded end and its inner end cutto form an incline, and a set screw having a conical inner end threadedinto the extension, said conical end engaging with the plugs to forcethem outwardly against the collar.

2. In combination, a boring bar having a transverse opening, mounted inthe opening, a pivotally mounted backing member in the opening againstwhich the cutter engages, an extension to the bar at its forward end, acollar adjustablv mounted thereon and having a rear guiding lace adaptedto aline the cutter, and means to lock the collar in any position to acutter loosely and means to lock the collar in fixed relation to theextension, substantially as described.

In testimony whereof I aiiix my signa' ture in presence of twowitnesses. FRANK DIEBOLD. Witnesses:

ALBERT A. GRIFFIN, FRANK. Buss.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

Washington, D. G.

